Error in creation of custom view - android

i have customview, i want to add that in the xml file i tried like this but i am getting this error
Custom view TouchImageView is not using the 2- or 3-argument View constructors;
XML attributes will not work
this is the xml i am using..
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<view
class="com.zoom.TouchImageView"
android:id="#+id/webView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>

Add the constructor:
public TouchImageView(Context context, AttributeSet attributeSet)
{
super(context, attributeSet);
//TODO:
}
to your custom View class.

Related

CustomView with xml doesn't show up on screen

I am trying to add my custom view to the main activity's xml.
I have created the following xml for the view:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Testing custom view"
android:textSize="20dp" />
</LinearLayout>
And created the following class in which the above xml is inflated:
public class TestView extends LinearLayout {
public TestView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
View.inflate(context, R.layout.test_name, null);
}
And in the xml of the main activity I have added the custom view like below:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.myapplication.MainActivity">
<com.example.myapplication.TestView
android:id="#+id/submit_area"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
When I am running the app, I am getting an empty screen. It's not showing the textview which displays "Testing custom view".
Any help would much appreciated.
Thanks
Your view inflation code in your custom view looks wrong.Try it the way given below.
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.view_color_options, this, true);

Avoid un-necessary view nest when create custom view together with xml resource

I am trying to create a custom view, and I extends from LinearLayout:
public class CustomView extends LinearLayout {
private ImageView mPrevImgView;
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
View root = ((LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.custom, null);
this.addView(root);
mPrevImgView = root.findViewById(R.id.xx);
....
}
}
And the layout/custom.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/xx"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
.......
</LinearLayout>
Then I try to use it this way:
<CustomView android:layout_width.....>
...
</CustomView>
This works as expected.
However it seems that the CustomView itself is a LinearLayout, and it then add another LinearLayout in the constructor, this cause two LinearLayout nested which is unnecessary. I wonder if it is possible to avoid this?
// try this way
**custom.xml**
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/xx"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"/>

Custom view in xml layout not working

I'm trying to add a subclass of View to my activity_main.xml like this.
However, the device and emulator drop out of the app straight away. The error appears to be Error inflating class com.example.androidtest.PuzzleView
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.example.androidtestapp.PuzzleView
android:id="#+id/puzzleView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="60"/>
<include
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="40"
layout="#layout/activity_input"/>
</LinearLayout>
and
package com.example.androidtestapp;
public class PuzzleView extends View {
public PuzzleView(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
}
}
I think the problem is you need to have a constructor with AttributeSet attrs as a parameter
public PuzzleView(Context context, AttributeSet attrs) {
super(context, attrs);
//code
}

Android. How to adjust height and width of a custom component using XML attributes?

Is there any way to adjust height and width of a custom component using XML attributes?
For example, I created a component and its layout.
Here is XML layout of the component:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<TextView
android:id="#+id/textView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
<TextView
android:id="#+id/textView3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="TextView" />
</LinearLayout>
And here is a simple class that inflates this layout:
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context, AttributeSet attrs)
{
super(context, attrs);
LayoutInflater inflater = (LayoutInflater)context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
ViewGroup view = (ViewGroup)inflater.inflate(
R.layout.custom_component, null);
addView(view);
}
}
The custom component is used in layout of some activity that looks something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<view
class = "com.tests.CustomComponent"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>
The component is meant to be stretched to full size of a screen (that's why its layout parameters set to "fill_parent") but that is never happen.
Can anyone help me with this?
Seeing as your CustomComponent extends LinearLayout, you just need to inflate the layout directly into it (parsing this as the ViewGroup, as your CustomComponent will be the holding view):
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context, AttributeSet attrs)
{
super(context, attrs);
inflate( context, R.layout.custom_component, this );
}
}
If that doens't work, try supplying only the constructor that takes a context:
public class CustomComponent extends LinearLayout
{
public CustomComponent(Context context)
{
super(context);
inflate( context, R.layout.custom_component, this );
}
}

Android: Same xml acts differently depending on where I inflate it and I don't know why

Why do some views in a linearlayout within a scrollview fill the parent when fill_parent is set when inflated from xml directly but don't when added via a custom component that inflates the same xml?
The result of inflating the same xml in two different places:
The top item of the two is as a result of inflating the xml in a class that extends linearLayout and then adding that class to the linearLayout inside the scroll view. This view isn't filling the parent and I can't work out why.
The bottom item is the result of inflating the xml directly in the activity that this is all contained within. It appears as I expected.
This is the code that adds the two views in the activity:
scrollList.addView(new CommunityTaskListItem(this, null));
scrollList.addView(View.inflate(getBaseContext(), R.layout.communitytask, null));
This is the code that inflates the activity within a custom component class "CommunityTaskListItem":
View communityTask = View.inflate(context, R.layout.communitytask, null);
addView(communityTask);
I assume the xml is okay because it works fine when inflated directly in the activity. My question is why the fill_parent property seems to be lost when the xml is inflated in a custom component's class?
For good measure, here is the xml being inflated: EDIT: I gave you the wrong one before!!! Here's the right one:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent" android:layout_height="wrap_content">
<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="#+id/linearLayout1" android:background="#drawable/plainbutton" android:layout_marginBottom="5px" android:layout_marginTop="5px" android:layout_weight="1">
<TextView android:layout_height="wrap_content" style="#style/CommunityTaskText" android:layout_width="fill_parent" android:layout_weight="1" android:id="#+id/textViewCommunityTaskTimes" android:text="xx:xx - xx:xx"></TextView>
<TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" style="#style/CommunityTaskText" android:id="#+id/textViewCommunityTaskDescription" android:text="Task"></TextView>
</LinearLayout>
</LinearLayout>
I'd like to keep the custom component and not inflate the xml within my activity if I could.
EDIT: Code where CommunityTaskListItem is inflated:
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
public class CommunityTaskListItem extends LinearLayout {
TextView textViewCommunityTaskTimes;
TextView textViewCommunityTaskDescription;
public CommunityTaskListItem(Context context, AttributeSet attrs) {
super(context, attrs);
View communityTask = View.inflate(context, R.layout.communitytask, null);
addView(communityTask);
textViewCommunityTaskTimes = (TextView)findViewById(R.id.textViewCommunityTaskTimes);
textViewCommunityTaskDescription = (TextView)findViewById(R.id.textViewCommunityTaskDescription);
}
...
EDIT: All working now! Here's the final code for anyone else incase they have a similar issue:
Contructor for the custom object:
public CommunityTaskListItem(Context context, AttributeSet attrs) {
super(context, attrs);
setOrientation(VERTICAL);
addView(inflate(context, R.layout.communitytask, null));
textViewCommunityTaskTimes = (TextView)findViewById(R.id.textViewCommunityTaskTimes);
textViewCommunityTaskDescription = (TextView)findViewById(R.id.textViewCommunityTaskDescription);
}
Custom object xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="#+id/linearLayout1" android:background="#drawable/plainbutton" android:layout_marginBottom="5px" android:layout_marginTop="5px" android:layout_weight="1">
<TextView android:layout_height="wrap_content" style="#style/CommunityTaskText" android:layout_width="fill_parent" android:layout_weight="1" android:id="#+id/textViewCommunityTaskTimes" android:text="xx:xx - xx:xx"></TextView>
<TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" style="#style/CommunityTaskText" android:id="#+id/textViewCommunityTaskDescription" android:text="Task"></TextView>
</LinearLayout>
</LinearLayout>
To be honest I don't know exactly what the mistake I was making was so if someone could make that clear I'd be very grateful.
The first line should be:
scrollList.addView(new CommunityTaskListItem(this, null)
new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
You call inflate() inside CommunityTaskListItem class and inflated view becomes a child view of the CommunityTaskListItem view. But you don't set width and height for this view so it doesn't match its parent's width.
EDIT: I think your XML should look like this:
<?xml version="1.0" encoding="utf-8"?>
<packagename.CommunityTaskListItem
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent" android:layout_height="wrap_content">
<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="#+id/linearLayout1" android:background="#drawable/plainbutton" android:layout_marginBottom="5px" android:layout_marginTop="5px" android:layout_weight="1">
<TextView android:layout_height="wrap_content" style="#style/CommunityTaskText" android:layout_width="fill_parent" android:layout_weight="1" android:id="#+id/textViewCommunityTaskTimes" android:text="xx:xx - xx:xx"></TextView>
<TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" style="#style/CommunityTaskText" android:id="#+id/textViewCommunityTaskDescription" android:text="Task"></TextView>
</LinearLayout>
</packagename.CommunityTaskListItem>
where packagename is the name of the package of the CommunityTaskListItem class.
In this case you should change the CommunityTaskListItem:
public class CommunityTaskListItem extends LinearLayout {
TextView textViewCommunityTaskTimes;
TextView textViewCommunityTaskDescription;
public CommunityTaskListItem(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onFinishInflate() {
textViewCommunityTaskTimes = (TextView)findViewById(R.id.textViewCommunityTaskTimes);
textViewCommunityTaskDescription = (TextView)findViewById(R.id.textViewCommunityTaskDescription);
}
// ....
}
This class cannot be created using its constructor. It can be only inflated.
The second way is to inflate children in the constructor like you do. But the XML should differ:
<?xml version="1.0" encoding="utf-8"?>
<merge
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="#+id/linearLayout1" android:background="#drawable/plainbutton" android:layout_marginBottom="5px" android:layout_marginTop="5px" android:layout_weight="1">
<TextView android:layout_height="wrap_content" style="#style/CommunityTaskText" android:layout_width="fill_parent" android:layout_weight="1" android:id="#+id/textViewCommunityTaskTimes" android:text="xx:xx - xx:xx"></TextView>
<TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" style="#style/CommunityTaskText" android:id="#+id/textViewCommunityTaskDescription" android:text="Task"></TextView>
</LinearLayout>
</merge>
The CommunityTaskListItem will be:
public class CommunityTaskListItem extends LinearLayout {
TextView textViewCommunityTaskTimes;
TextView textViewCommunityTaskDescription;
public CommunityTaskListItem(Context context) {
this(context, null);
}
public CommunityTaskListItem(Context context, AttributeSet attrs) {
super(context, attrs);
setOrientation(VERTICAL);
inflate(context, R.layout.communitytask);
textViewCommunityTaskTimes = (TextView)findViewById(R.id.textViewCommunityTaskTimes);
textViewCommunityTaskDescription = (TextView)findViewById(R.id.textViewCommunityTaskDescription);
}
// ....
}
This class can be created using its contructor and inflated from an XML. But if you want to inflate it, you should create a separate XML file. Let's call it task.xml.
<?xml version="1.0" encoding="utf-8"?>
<packagename.CommunityTaskListItem
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="wrap_content"/>
And that's how you can use it:
scrollList.addView(new CommunityTaskListItem(this),
new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
scrollList.addView(View.inflate(getBaseContext(), R.layout.task, null));

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